Chem. J. Chinese Universities ›› 2020, Vol. 41 ›› Issue (7): 1631.doi: 10.7503/cjcu20200099

• Physical Chemistry • Previous Articles     Next Articles

Synergism Between Asphaltene and Its Subfractions and Alkylbenzene Sulfonate Solutions in Lowering Dynamic Interfacial Tensions

JIA Xuemei,CHENG Tiexin,ZHOU Guangdong*()   

  1. College of Chemistry, Jilin University, Changchun 130023, China
  • Received:2020-02-27 Online:2020-07-10 Published:2020-04-08
  • Contact: Guangdong ZHOU E-mail:zhougd@jlu.edu.cn
  • Supported by:
    Scientific Research Project of Petrochina Daqing Oilfield Co., Ltd., China(DQYT-1204003-2015-JS-824)

Abstract:

Asphaltene extracted from Daqing crude oil was separated into four subfractions by precipitation method of mixed solvents. The dynamic interfacial tensions(DIFTs) of alkylbenzene sulfonate(p-S14-4) aqueous solutions against model oil containing asphaltene and its subfractions were measured. The results revealed that the molecular size, concentration and polarity of asphaltene and its subfractions had a significant effect on DIFTs. For asphaltene subfractions with larger molecular size, DIFTs curves presented the "L" shape and minimum interfacial tension(IFTmin) had a slight variation with the concentration and polarity, because the formation of mixed adsorption films between them and p-S14-4 molecules was difficult. For asphaltene and its subfractions with smaller molecular size, at high concentrations, these subfractions quickly diffused to the interface to form a tightly mixed adsorption film with p-S14-4 molecules, which can instantly lower the interfacial tension(IFT); with time going on, the molecules at the interface layer rearranged. As a result, the DIFTs curves presented "V" shape. Moreover, in this case, asphaltene and its subfractions with higher polarity resulted in lower IFTmin because of the more obvious synergism.

Key words: Asphaltene, Interfacial tension, Synergism, Molecular size, Concentration

CLC Number: 

TrendMD: